1. Field
Embodiments of the invention relate to the field of semiconductor fabrication, and more specifically, to wafer processing.
2. Background
Semiconductor devices are fabricated in an array on a wafer. The semiconductor devices are typically separated by vertical and horizontal scribe lines. The wafer is processed, cut or diced, through the scribe lines to singulate the devices from one another. Traditionally, the cutting process is performed with wafer spindle and blade assemblies having cutting blades with various shapes. To hold the wafer in place while cutting, a tape is attached to the surface of the wafer.
To obtain precision in cutting, the saw blade is aligned with the scribe lines. Traditional techniques to align the saw blade use optical alignment systems. In these systems, a charge coupled devices (CCD) camera captures the etching pattern of the scribe lines. The pattern information is then transmitted to a computer having appropriate vision or pattern recognition software to control the mechanical system and assembly that position the saw blade. The cutting process is then performed on the active side or front side of the wafer. Cutting from both the front and back sides may have many undesirable effects. These include the generation of shards and particulates during sawing. In addition, the alignment may not be accurate due to sensor errors.